Is this correct?
When I see a bouquet of flowers (many flowers in a bouquet) can I say:

"Whose flowers are those? Who brought them?"
Or Whose flower is that? Who brought it?

Thank you.

Question

Is this correct?
When I see a bouquet of flowers (many flowers in a bouquet) can I say:

"Whose flowers are those? Who brought them?"
Or Whose flower is that? Who brought it?

Thank you.

Answer

“Whose flowers are those? Who brought them?” sounds the most natural to me.

Answer

A bouquet is a bunch (several) of flowers. 
Bouquet is singular. Flowers are plural.
Use: Whose flowers are those? Who brought them? Whose bouquet is that? Who brought it?

Answer

Lo correcto sería: ¿De quién son esas flores?, ¿Quién las trajo?